Missing "encoding" panel/tab
I don't think that AVI Raw has encoding options.

As it's an uncompressed format you'll not have much setting to work with, they are just plain frames. 

The purpose of this format is to provide an input video that will be mixed and encoded with sync audio in a second phase, after for example some compositing, or color correction. It's the RAW data, it is expected to be used as a "base", not to be the final result.

You can Mixdown to extract audio from your file and than mix them with video in Blender or an external application.

Note: I wasn't able to find out any evidence of the fact that Blender AVI Raw format, despite its name, is not able to contain audio (and I'm not even sure), so consider this as a personal opinion.

You should use another output format.